The present invention relates to a system for forming concrete slabs and beams. More particularly, the present invention relates to a concrete forming system having a slab form and shoring towers, wherein the slab form can be removed from a cured slab while the shoring towers remain in place to permit complete curing of the beams.
Modern post-tensioned concrete parking garages are constructed with very deep beams which require very strong shoring because both the weight of the slab and the weight of the beam itself are gathered to the beam shore when the slab tendons are pulled. Traditionally, the slab soffit is constructed between 9 and 10 feet in height and the deep beams are constructed to provide around 61/2 to 71/2 feet of clearance for movement of forming and shoring equipment.
Traditionally, post-tensioned concrete parking garages have been built using slab forms, shoring frames and beam forms of lumber and plywood which are taken apart as the forms are stripped from the concrete, stacked on dollies, and towed up the ramps to be reused in forming the next level of slabs and beams. The nailing, stripping, renailing, and handling of the wood damages the wood, and is both labor intensive and time consuming.
Aluminum beams having 2.times.2 nailers have also been used in the construction of post-tensioned concrete parking garages, but the aluminum beams suffer the disadvantage that they also must be handled individually several times in stripping and resetting.
Another system for construction of post-tensioned concrete parking garages uses a steel beam form with steel tubular shoring towers having legs which fold flat so that the shoring tower can be lowered with a fork lift onto dollies and then towed beneath existing shoring and beams to another level for further use. The steel beam form method requires that the beam forms on one level be stripped and moved before any of the slab or other beam forms can be transported to another location for re-use. That method is also labor intensive and time consuming.
Accordingly, a need has arisen for a faster and more efficient way of constructing poured in place, multilevel parking garages without the use of cranes.
It is, therefore, an object of the present invention to provide a concrete slab and beam forming system which can be used quickly and easily, without the necessity of disassembling and re-assembly.
Another object of the present invention is to provide a concrete slab form which can be released from a poured concrete slab after the concrete has cured which is provided with folding edge wings on each side capable of becoming the legs of the slab form when folded down.
A further object of the present invention is to provide a self-contained, stable slab form having casters on the ends of pivotally attached planks so that the form can be moved between and under existing shoring towers and beam forms to another location for reuse.
It is yet another object of the present invention to provide a system for construction of concrete slabs and beams which permits the pouring of large sections of slab and beam all at one time.
Yet another object of the present invention is to provide a slab deck form which can be stripped and reused during the additional period of time required for the concrete in the beam forms to cure even though both forms were poured at the same time.
A further object of the present invention is to provide a concrete slab and beam forming system which is inexpensive and light in weight.
Another object of the present invention is to provide a concrete slab form and beam form system wherein sufficient clearance is provided for moving equipment beneath beam forms and between shoring tower legs.
A further object of the present invention is to provide a concrete slab and beam forming system in which continuity of long spans of beam forms and shoring towers can be achieved.
Another object of the present invention is to provide a rollable slab form which does not require separate dollies for moving and which can be transported to a new location ready to be installed in place for pouring of concrete.
Yet another object of the present invention is to provide a concrete slab and beam forming system having a shoring tower and beam form which is capable of retracting from about 91/2 feet to about 5 feet in height, thereby being capable of supporting a slab or deck at any of the heights likely to be required for construction of most poured in place concrete structures.
A further object of the present invention is to provide a concrete slab and beam forming system which can be constructed of wood, thereby reducing the costs and construction time required for constructing post tensioned concrete parking garages and other similar buildings.
Yet another object of the present invention is to provide a concrete slab and beam forming system which is safer to use than those currently available because the slab form is a more stable unit and the beam form weighs less and has stable 4 leg towers when being moved.
These and other objects of the present invention will become evident to those skilled in the art who have the benefit of the description of the preferred embodiment which follows.